This comparison covers Efficiency of Common Devices within Efficiency for GCSE Physics. Revise Efficiency in Energy for GCSE Physics with 19 exam-style questions and 4 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 13 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.
⚖️ Efficiency of Common Devices
| Device | Input Energy | Useful Output | Efficiency |
|---|---|---|---|
| Incandescent bulb | Electrical | Light | ~5% |
| LED bulb | Electrical | Light | ~40–50% |
| Petrol car engine | Chemical (fuel) | Kinetic | ~25% |
| Electric motor | Electrical | Kinetic | ~90% |
| Solar panel | Light (solar) | Electrical | ~15–22% |
| Human body (walking) | Chemical (food) | Kinetic | ~25% |
Practice questions for Efficiency
Which equation correctly defines efficiency?
Explain one method that can be used to reduce unwanted energy transfers in a machine and state how it reduces waste.
Quick recall flashcards
As a decimal
0.85 (between 0 and 1)
As a percentage
85% (multiply decimal by 100)